Computed BOM Overview
Computed BOMs list the components and sub-assemblies in a SolidWorks
assembly or drawing. They are recalculated each time you view them. If
you check in a changed assembly or select a different version or configuration,
the computed BOM is updated when you view it.
Computed BOMs reflect exclusions you make in SolidWorks files. Components
marked as Exclude from bill of materials
and child components excluded from sub-assemblies do not appear.
You can check out selected items that are listed in a computed BOM,
and modify data values for these items. The computed BOM is updated when
you check
in the assembly document. If you edit properties or quantities
in a computed BOM, the BOM is updated when you save it.
However, you cannot:
Add items to a computed BOM.
Check in or check out computed BOMs.
Use computed BOMs in a workflow.
Access rights assigned by your administrator determine whether you can
view a computed BOM.
To edit a computed BOM and save the changes:
Check
out the assembly or part used to create the BOM.
On the Bill of
Materials tab in the file
view, select the computed BOM 
for the assembly, click Save BOM 
, and
select Save.
To display a computed BOM in the Bill
of Materials View:
Select the computed BOM for
an assembly or drawing from the BOM
list and select Activated.
To compute the bill of materials for set of files in
a folder:
For all the documents to list in the BOM, reference
all but one of the documents to the remaining document.
From a computed BOM on the Bill of Materials tab, select Show Selected.
Related Topics
Saving
a computed BOM as a named BOM
Editing
quantities or other referenced variables in a computed BOM
Changing
the computed BOM display